\documentclass{article}
\usepackage{amssymb,amsmath,amscd,concmath}
\pagestyle{empty}
\begin{document}
\begin{equation*}\lim_{v\to 0}{\left( \frac{1}{\sqrt{1- v^2/c^2\ }} - 1 \right) m c^2 \over mv^2/2}=1\end{equation*}
\end{document}
